Why did fighting begin at Dublin’s Four Courts in 1922?

Fighting began at the Four Courts in Dublin in June 1922 due to a deep ideological split within the Irish nationalist movement following the signing of the Anglo-Irish Treaty in 1921.12

The treaty, which established the Irish Free State as a dominion within the British Empire, required members of the Irish parliament to pledge an oath of allegiance to the British monarch. This provision was unacceptable to many republicans, leading to a fracture in both the political party Sinn Féin and the Irish Republican Army.23

In April 1922, anti-treaty members of the IRA seized the Four Courts, the center of the Irish judicial system. While the pro-treaty Provisional Government, led by Michael Collins, initially hesitated to attack their former comrades, they were eventually pressured by the British government to restore order. On June 28, 1922, government forces fired on the building, an act that effectively ignited the Irish Civil War.24